Why not just do propane? I have no clue but thinking that's easier and more gains.

Lots of info on that out there to compare propane vs Nitrous vs H2O/methanol. Tend to not be convinced propane is a good option, but have no direct experience with it.

Aspects I like about the water injection are the cleaning properties and EGT/particulate reduction. Direct injected, EGR equiped engines can get carbon build up in the intakes very easily and the water injection helps keep things clean, as well as reduce peak cylinder pressures when extra fuel is being added. Direct measurements with the BT tool show good EGT reductions on the D.

how much is more tDI? is dangerous 600ml of water inje at max Flow for the 3000cc bmw ?

Good question. This is an area where more is definitely not always better. And lots of good published journal articles (from sources not selling products) are available regarding impacts to/from water/alcohol injection.

There's some info online about sizing injectors based on engine displacement, boost, max rpm, etc. (for example http://www.alcohol-injection.com/en/nozzle-selector.php). The BT data (EGT's and boosted intake air temps) and AEM flow guage were useful for zeroing in on the current setup. And ongoing oil analysis and constant monitoring of engine operating parameters shows the engine is working well with things as they are. Considering the calculator linked above the current setup is just slightly higher than their recommended flow rate.

As a side note, the DDE doesn't seem to like it if you inject at low boost/load conditions. It can set a "pending" code in these cases. But no problems yet observed with waiting until near max boost conditions exist before engaging injection.

Lots of info on that out there to compare propane vs Nitrous vs H2O/methanol. Tend to not be convinced propane is a good option, but have no direct experience with it.

Aspects I like about the water injection are the cleaning properties and EGT/particulate reduction. Direct injected, EGR equiped engines can get carbon build up in the intakes very easily and the water injection helps keep things clean, as well as reduce peak cylinder pressures when extra fuel is being added. Direct measurements with the BT tool show good EGT reductions on the D.

You are running 70% water? Is there any advantage/harm in trying 100% methanol?

Also, my car is due for the EGR recall, programming update. Any feedback on whether this increases/decreases HP? I know half the owners have complained about mpg decreases.

I was looking at the new mixer diffuser they install during the recall, doesn't that thing look restrictive? Has anyone tried running without it?

You are running 70% water? Is there any advantage/harm in trying 100% methanol?

Also, my car is due for the EGR recall, programming update. Any feedback on whether this increases/decreases HP? I know half the owners have complained about mpg decreases.

I was looking at the new mixer diffuser they install during the recall, doesn't that thing look restrictive? Has anyone tried running without it?

Thanks for the pic of the diffuser.

The EGR recall impacted the initial tank mpg's, but the car seemed to adapt rapidly and fuel efficiency returned to normal after that.

Do not have any quantifiable data on before/after power #'s.

Been running just over 50% H2O lately in the d and my Cummins powered Wrangler.

Good question on straight methanol. I've attached a link to an excellent thesis on alcohol injection in diesel engines that also summarizes a lot of previous research. Some areas related to your question that make me think going above ~100 proof (50% alcohol/50% water) is a bad idea is the issue with the peak cylinder pressures and rate of pressure rise (effectively advancing timing). Plus above ~50% alcohol the combination is flammable. And if one is using the OEM washer fluid container as the source of liquid . . .

"Baranescu [19] performed alcohol fumigation experiments on a six-cylinder, turbocharged, direct-injection, 7.1-L diesel engine. The alcohols used were methanol, 190-, and 160-proof ethanol. Her results reported that alcohol fumigation caused a substantial increase in maximum in-cylinder rates of pressure rise and peak in-cylinder pressures when compared to regular diesel operation. She concluded that this should be a limiting factor to be taken into account when alcohol fumigation is to be used.

"They concluded that, in general, it is possible for the NOx emissions to be substantially reduced by alcohol fumigation. This reduction in NOx is more pronounced with lower ethanol proofs, as the increased amounts of water help decrease the peak combustion temperatures."

"The vaporization of ethanol tends to cause a pronounced
charge cooling which lowers the in-cylinder temperatures prior to ignition, thus increasing the ignition delay. A long ignition delay may result in a large amount of ethanol being introduced into the cylinder before ignition occurs. Under such conditions, the combustion of a large mass of fuel results in very rapid burning rates with high rates of in-cylinder pressure rise and high in-cylinder peak pressures. Under extreme conditions, the combustion proceeds so rapidly that an audible knocking sound can be discerned the so-called diesel knock . Under low engine loads, however, the ignition delay caused by the ethanol can become so large that the combustion occurs
very late in the expansion stroke. This results in the quenching of the combustion process, resulting in low peak pressures and temperatures, incomplete combustion, reduced power output, low thermal efficiency, and increased HC and CO emissions (see below). Engine knocking (at high loads) and mis re (at low loads) are usually the factors that limit the maximum amount of ethanol that can be fumigated into a diesel engine. The water contained in lower-proof alcohols appears to inhibit pre-combustion reactions that cause engine knocking."

"Question regarding tire size from a dragsrip newbie for those more experienced:

Used 245/45R17 Hoosiers which have a 26.2 in diameter (correction, it's 26.0 based on the manufacturers website). This is significantly larger than stock wheel size and pushes the 4th-5th shift up to ~111mph. Thought this would be high enough that the car wouldn't waste time shifting into 5th during the pull, and more than make up for the slower acceleration at the beginning from the larger tires. However, looking at the recording of the pull (used the Track Recorder option the Android Torque app, and overlaid rpm data on the display) it shows the car was going a bit faster than anticipated and did the 4th-5th shift just before crossing the finish line. So the car was just getting into 5th gear as it went through the trap and finish line.

Would it be better to move to a lower diameter tire and have the 4-5 shift occur before the trap, so the car isn't coasting through the line, and also get better starting acceleration? Or is the larger diameter tire a better option?"

"Question regarding tire size from a dragsrip newbie for those more experienced:

Used 245/45R17 Hoosiers which have a 26.2 in diameter (correction, it's 26.0 based on the manufacturers website). This is significantly larger than stock wheel size and pushes the 4th-5th shift up to ~111mph. Thought this would be high enough that the car wouldn't waste time shifting into 5th during the pull, and more than make up for the slower acceleration at the beginning from the larger tires. However, looking at the recording of the pull (used the Track Recorder option the Android Torque app, and overlaid rpm data on the display) it shows the car was going a bit faster than anticipated and did the 4th-5th shift just before crossing the finish line. So the car was just getting into 5th gear as it went through the trap and finish line.

Would it be better to move to a lower diameter tire and have the 4-5 shift occur before the trap, so the car isn't coasting through the line, and also get better starting acceleration? Or is the larger diameter tire a better option?"

Any insight for a 1/4 mile newbie would be appreciated.

Good info on that meth injection! Diesels are such a different animal.
I just used the same tires from my 335i on the 335d. Nitto NT555Rs on, 275/40/17's. They are a little taller. So on the gas car, I actually got better times with the taller tires. It allowed me to hit 60mph easily in 2nd gear, and finish the 60-130 times before the shift into 5th gear. Not how this comes into play with the diesel. With its taller gearing, I would imagine smaller diameter "could" be better. I would have to see the gear shift point, and how it relates to the qtr mile. I was just doing some preliminary testing this morning on the Stock RFTs still. They are very slippery, yielding 2.3 sec 60' times, and not allowing me to launch with any boost at all. Still mid 13's. A 1.9 sec 60' times should be solid high 12 second runs. Not sure if this is with the JBD set at 75% or 100%. It has been so long since I ran this car, I don't remember the setting. Perhaps I will do a video next time showing the shift points. Actually, you can probably tell the shift points by my you tube video. I'm pretty sure today the car was shifting at 4500rpm. Is that what yours does. I assume no need to go to 5000rpm. But i'm surprised the car shits so early from the factory. 2nd gear launch, and just letting it shift by itself afterwards.

looks like it might be shifting right before the end of the qtr mile. And that is with the taller DRs in this video.

I read many of your threads and watched this same video when trying to learn better ¼ ml techniques. Thanks for sharing that stuff.

The data I had collected practicing with launching on the Michelin Pilot Super Sports (after the first trip to the strip with lots of traction issues), and then comparing to the Hoosiers, is here with posts 79 and 83:

Looking at the various GTech HP/rpm data in that thread it seemed obvious to me that the hp starts rolling off above ~ 4400/4500 rpm. And the HP curve is such that it’s nearly constant from ~3500-4400 which is about perfect for the gearing of the vehicle (the car seems to self shift at ~4600 brings you back down to ~3600 and at about the same power).

Looks like the NT555 in 275/40R17 are 25.6 in diameter, so they’re a little smaller than the 26.0 of the Hoosier 245/45R17.

Looking at my track recording (and pausing the playback at specific points) the car self initiated the 4/5 shift at ~4600 rpm just before entering the trap and the rpm’s fell to ~3600rpm (5th gear engaged) as the car was just passed the finish line. Using GPS data and rpm’s I had calculated 4600 rpm with the Hoosiers in 4th gear as being ~111mph. So with the 25.6 Nitto’s I’d guess your car did the 4/5 shift at ~ 109 (circumference is proportional to diameter, so 111*25.6/26). Of course depending upon tire air pressures the difference could be more/less. I had my Hoosiers at 27psi for the run, which is pretty high.

I’m inclined to think at this point the car has enough power to cause the 4/5 shift to occur during the run anyway, so it would be better to move to a lower diameter tire and gain some gearing advantage.

I agree. There is no more effective tool for gauging your car's performance than a GPS performance meter. I have a Vbox Performance Box, and A Gtech Fanatic. On the Vbox, I can run 3 consecutive runs and have a 1/4 mile trap within a few tenths of a mph. The slightest change in HP will show up. Funny how some of these guys with huge HP dyno results often underperform at the dragstrip.

Improved just a tad today from last years 12.69 to a 12.65 today, with less favorable conditions.

Today was opening day at the nearest 1/4 mile track. Wasn't planning on going until the night before when an obligation got canceled. So, I was able to try some of the new things, but the car wasn't optimally prepared. It had too much fuel (2/3 full of fuel) and the temps were a little warmer than last year. Oh well, it was still a chance to learn.

The car was heavier by 50-60 lbs from last year due to more fuel and more urea. More urea in the tank than last year (last years run was very close to the yearly maintenance and today was less 1/2 way to the yearly service). The temps were pretty good at ~65F, but that was ~18F warmer than last years run.

Also used slightly smaller diameter drag radial. Last years run was larger than stock diamter 245/44/R17 drag radials. Todays was with 225/45R17's which are close to stock diamater.

So, a recap of differences from last year include:
1.) 225/45R17 drag radials vs last years 245/45R17
2.) Customized the water/methanol injection. I made a circuit modification to the Snow boost based controller that creates
a 2D controller ... It now works based on boost AND rpm. Our cars make max boost happens at the lower rpm's and then taper off slighter at higher rpm's. This causes a problem with a boost only controller as you can bog down at the lower rpm's
if you have things setup for optimum higher rpm performance. So now it has an additional rpm component. It will
turn on if enough boost is present (adjustable level) AND based on a minimum rpm (adjustable). If those are satisfied
the output is proportional to rpm's. At full fueling the water/methanol starts at ~2000 rpm's at ~350ml/min and maxes out
at ~4500 rpm at 700 ml/min. Both last and this year used 50/50 mix.
3.) 65F this year vs 47F last year.
4.) ~60 lbs heavier than last year.
5.) Stock intake, stock intercooler, stock exhaust, stock differential... same as last year.

The smaller diameter tires helped the times, even with the heavier vehicle. But I'm at a frustrating point where the 4-5 shift is occurring right at the 1/4 mile point. The top speed is a tad slower this year even though the time is quicker. The smaller tire caused the 4-5 shift to occur before the 1/4 mile point. The shift point causes a loss of application of power as during the shift the power output is cut to help the transmission's longevity ... Last year the larger diameter tire caused the shift to occur right as I was crossing the line. This year with smaller tire it happened right before ... Not sure how to optimize this problem any further. Basically I can trade off a faster 1/4 mile ET with the larger tires, but a faster 1/4 mile time with the smaller tires. Think for real world/street application the smaller diameter tire is the way to go.

Had a great time chatting with the former BMW tech I met during last fall's run. He was there with his car, but broke something in his drivetrain on his 2nd run. He had a co-worker who was the diesel calibration technician at a major heavy duty ag company ... we went over the car, what mods it had, and what he's seen in real world applications for his companies modern diesels (EGR, SCR, DPF, Carbon buildup, how to work around emission components ...). Was fantastic to have a face to face with someone who knows their modern diesel technology.

So basically what I'm seeing is that to significantly increase capability will get really, really expensive and make the car less user friendly and emission clean. I'm not keen on removing the DPF due to the smoke/stink. And at this point it doesn't seem to be causing any performance issues. Think I'm probably at the end of my tweaking on this vehicle as its my main ride now and having something I can daily drive in all conditions (except deep snow) is a priority. I may go back again to the track if the weather is perfect and I have time to get the car in the proper condition (~1/8 tank of fuel, lower urea capacity, cooler temps... strong tail wind :-)).

Well, that car has an Evolve remap, stacked with a customized JBD that progressively adds pwr based on rpm, and H2O/methanol injection at ~650 ml/min (based on AEM flow gauge data) at max boost. But the IC is stock. The H2O injection pulls intake temps down below ambient temps even on hot summer days on multiple pulls based on Bavarian Technic logged data.

The progressive JBD mod is key to keeping torque levels below the rated capacity of the transmission. It's only adding in pwr after the remap torque curve is starting to fall off. It's below the stock "0" setting until ~2500rpm and peaks at ~90-95% at 4400rpm. Makes for a nice, broad torque curve. It's also nice because the rail pressure distortion is at near stock levels during the rpm's where the ECU's injector calibration adaptation routine occurs.

The remap also increases boost for better utilization of the extra fuel (less soot formation and loading of the DPF), and the H2O injection reduces peak cylinder pressures and NoX formation, as well as further reduces soot formation (based on published papers).

It's been a good combo over the last several months which gives good performance and efficiency with little fuss. And it doesn't use much H20/methanol (fill the washer fluid resevoir about once every 1-2 months). Largely because it doesn't use much boost unless you get on it, and then you're speeding before you know it . . .

The boosted air intake temp, post intercooler, is measured by part #16. I did verify this with the BT by unplugging the connector and checking the recorded IAT's. As an FYI, the DDE doesn't like it if the IAT's are significantly higher or lower than the temp sensor by the air filter...